1. Field of the Invention
The present invention relates to an electronic circuit apparatus, more particularly to an electronic circuit apparatus capable of preferably being used, for example, in an ignition timing control apparatus of an internal-combustion engine for vehicles.
2. Description of the Related Art
FIGS. 1 and 2 are a plan view and a cross-sectional side view each schematically illustrating an electronic circuit apparatus for use in an ignition timing control apparatus of internal-combustion engine for vehicles. In these figures, a circuit board 1, in which circuit devices (not shown) are mounted, is housed in a housing 2. On the side wall portion of the housing 2 is provided a through portion 2a, in which a connector 3 is disposed via a bushing material 4 being formed of a elastic rubber material having a square cross sectional shape. The sealing of the connector 3 in the through portion 2a is effected by contacting the inner circumferential surface of the bushing material 4 with the outer circumferential surface of the connector 3 and fitting a recess 4a provided along three quarters of the outer circumference of the bushing material in the through portion 2a of the housing 2.
A terminal (not shown) of the circuit board 1 and pins of the connector 3 are connected to each other by a conductor 31, the other terminals of the connector 3 being electrically connected to an outside circuit (not shown) through an electrically insulated wire 32. The inside of the housing 2 is filled with a filling material 5 which has insulating properties such as an epoxy resin composition. This filling material 5 is not shown in FIG. 1.
The electronic circuit apparatus constructed as mentioned above is directly mounted, for example, on an engine block of a vehicle after it is assembled as shown in the figure, and it controls, for example, ignition timing via the wiring 32.
In the electronic circuit apparatus constructed as mentioned above, since sealing is effected by using an elastic bushing material 4 mounted between the housing 2 and the connector 3, there exists the problem in that the connector 3 vibrates separately from the housing 2 or the circuit board 1 due to vibrations of the engine, whereby connector terminals (not shown) or the circuit board 1, etc. are likely to be damaged owing to this vibration.